Some arctic tundra ecosystems receive as little precipitation as
deserts but have much more dense vegetation.

What climatic factor might explain this difference?

A.Tundra is much warmer than deserts, so less water evaporates
during the growing season and the tundra stays more
moist.B.Tundra is much cooler than deserts, so less water
evaporates during the growing season and the tundra stays more
moist.C.In addition to rain, tundra also receives water in the
form of snow.D.Tundra plants are better adapted to dry
conditions than desert plants.

B

13

Based on the data in the figure above, which of the following
statements are correct?I) Area 1 would be considered a desert
because of its high average temperature.II) Area 1 has more
average precipitation than Area 2.III) Area 2 would be
considered a desert because of its low average precipitation.IV)
Area 2 has a larger annual temperature variation.

A.only I and IIIB.only II, III, and IVC.only II and
IVD.only I, II, and IV

B

14

Based on the data in the figure above, which of the following
statements are correct?I) Area 1 has more average precipitation
than Area 2.II) Area 1 has a higher average temperature than
Area 2.III) Both areas have low variation in monthly
precipitation.IV) Area 2 has a lower annual temperature
variation compared to Area 1.

A.only II, III, and IVB.only I, II, and IIIC.only I and
IIID.only II and IV

B

15

Besides sunlight, which would be the next most important climatic
factors for terrestrial plants?

A.temperature and windB.wind and fireC.temperature and
moistureD.moisture and wind

C

16

Which of the following statements best describes the interaction
between fire and ecosystems?

A.Chaparral communities have evolved to the extent that they rarely
burn.B.The likelihood of a wildfire occurring in a given
ecosystem is highly predictable over the short term.C.Many kinds
of plants and plant communities have adapted to frequent
fires.D.The suppression of forest fires by man has prevented
certain communities, such as grasslands, from reaching their climax stage.

C

17

Fire suppression by humans _____.

A.is a management goal of conservation biologists to maintain the
healthy condition of forest communities.B.is necessary for the
protection of threatened and endangered forest species.C.can
change the species composition within biological
communities.D.will result ultimately in sustainable production
of increased amounts of forest products for human use.

C

18

If global warming continues at its present rate, which biomes will
likely take the place of the coniferous forest (taiga)?

The eight climographs below show yearly temperature (line graph and
left vertical axis) and precipitation (bar graph and right vertical
axis) averages for each month for some locations on Earth.

Which climograph shows the climate for location 1?

A.AB.CC.ED.H

A

20

Suppose that the number of bird species is determined mainly by the
number of vertical strata found in the environment. If so, in which of
the following biomes would you find the greatest number of bird species?

A.temperate grassland

B.savanna

C.temperate broadleaf forest

D.tropical rain forest

D

21

Which of the following is an important feature of most terrestrial biomes?

A.annual average rainfall in excess of 250 centimeters

B.vegetation demonstrating vertical layering

C.clear boundaries between adjacent biomes

D.a distribution predicted almost entirely by rock and soil patterns

B

22

In areas of permafrost, stands of black spruce are frequently
observed in the landscape, while other tree species are noticeably
absent. Often these stands are referred to as "drunken
forests" because many of the black spruce are displaced from
their normal vertical alignment. What is the most likely explanation
for the unusual growth of these forests in this marginal habitat?

A.Trees tip so that they do not compete with each other for
sunlight.B.Trees are tilted so snow prevents them from breaking
or tipping over.C.Taproot formation is impossible, so trees
developed shallow root beds.D.Branches are adapted to absorb
more carbon dioxide with this displaced alignment.

C

23

Two plant species live in the same biome but on different continents.
Although the two species are not at all closely related, they may
appear quite similar as a result of _____.

A.gene flow

B.convergent evolution

C.allopatric speciation

D.introgression

B

24

If carbon dioxide levels continue to increase and climate change
continues over the next century, which of the following would best
predict the directional migration of the North American ecosystems
from the biomes shown in this climograph?

A.The ecosystems will shift to the south due to decreasing
transpiration rates.B.The ecosystems will move down mountains as
the temperatures warm.C.The ecosystems will move to both the
eastern and western coastlines as these areas will be more
moderate.D.The ecosystems will shift to the north as
temperatures warm.

D

25

Based on the data in the figure above, which of the following
statements is true?

A.Area 2 could be tundra.B.Area 1 could be called a tropical
wet/rain forest.C.Area 1 could be called a boreal
forest/taiga.D.Area 2 could be called a temperate grassland.

B

26

Aquatic biomes cover approximately three-quarters of Earth's surface.
Examples of aquatic biomes include lakes, streams and rivers,
wetlands, estuaries, and oceans. Different types of aquatic biomes are
distinguished by their physical and chemical characteristics, their
depth, and, for some biomes, their distance from shore. Many temperate
lakes undergo semiannual turnover, a process that mixes the surface
and bottom waters, resulting in the redistribution of oxygen and nutrients.

Which of these is characteristic of the photic zone of a
freshwater biome?

In deep water, which of the following abiotic factors would most
limit productivity?

A.light availabilityB.temperatureC.solute concentration

A

28

Wetlands are standing bodies of freshwater, just like lakes and
ponds. However, wetlands are different from lakes and ponds because
wetlands have _____.

A.emergent vegetationB.oxygen-poor waterC.shallow water
and emergent vegetationD.emergent vegetation and oxygen-poor water

C

29

Which of the following statements regarding turnover in a lake is correct?

A.Fall turnovers and spring turnovers are exactly the
same.B.The surface water gets to 4°C only by cooling.C.In
fall turnover, dense water at 4°C rises and disturbs sediments in the
benthic zone.D.In fall turnover, dense water at 4°C sinks and
disturbs sediments in the benthic zone.

D

30

Which of the following types of organisms is likely to have the
widest geographic distribution?

A.bearsB.songbirdsC.bacteriaD.lizards

C

31

Which of the following can be said about light in aquatic environments?

Turnover of water in temperate lakes during the spring and fall is
made possible by which of the following?

A.cold, more dense water layered at the bottomB.warm, less
dense water layered at the topC.the changes in the density of
water as seasonal temperatures changeD.a distinct thermocline
between less dense, warm water and cold, dense water

C

33

Imagine that a deep temperate zone lake did not turn over during the
spring and fall seasons. Based on the physical and biological
properties of limnetic ecosystems, what would be the difference from
normal seasonal turnover?

A.An algal bloom of algae would result every spring.B.Lakes
would suffer a nutrient depletion in surface layers.C.The pH of
the lake would become increasingly alkaline.D.The lake would
fail to freeze over in winter.

B

34

If you are interested in observing a relatively simple community
structure in a clear water lake, you would do well to choose diving
into _____.

If a meteor impact or volcanic eruption injected a lot of dust into
the atmosphere and reduced the sunlight reaching Earth's surface by 70
percent for one year, which of the following marine communities most
likely would be least affected?

A.intertidalB.coral reefC.estuaryD.deep-sea vent

D

36

The oceans affect the biosphere by _____.I) producing a
substantial amount of the biosphere's oxygenII) adding carbon
dioxide to the atmosphereIII) being the source of most of
Earth's rainfallIV) regulating the pH of freshwater biomes and
terrestrial groundwater

A.only I, II, and IVB.only I and IIIC.only II and
IVD.only I, II, and III

B

37

Which of the following is responsible for the differences in summer
and winter temperature stratification of deep temperate zone lakes?

A.Stratification is caused by a thermocline.B.Winter ice sinks
in the summer.C.Water is densest at 4°C.D.Oxygen is most
abundant in deeper waters.

C

38

A certain species of pine tree survives only in scattered locations
at elevations above 2800 meters in the western United States. To
understand why this tree grows only in these specific places, an
ecologist should _____.

A.investigate the various biotic and abiotic factors that are unique
to high altitudeB.analyze the soils found in the vicinity of
these trees, looking for unique chemicals that may support their
growthC.collect data on temperature, wind, and precipitation at
several of these locations for a yearD.study the anatomy and
physiology of this species

A

39

Which of the following statements best describes the effect of
climate on biome distribution?

A.Average annual temperature and precipitation are sufficient to
predict which biome will be found in an area.B.Seasonal
fluctuation of temperature is not a limiting factor in biome
distribution if areas have the same annual temperature and
precipitation means.C.Correlation of climate with biome
distribution is sufficient to determine the cause of biome
patterns.D.The average climate and pattern of climate are
important in determining biome distribution.

D

40

In the development of terrestrial biomes, which factor is most
dependent on all the others?

A.consolidate a landscape region into a single
ecosystemB.determine if dispersal is a key factor in limiting
distribution of organismsC.develop mathematical models for
distribution and abundance of organismsD.determine the
distribution of a species in a specified area

Which of the following is true with respect to oligotrophic lakes and
eutrophic lakes?

A.Eutrophic lake water contains lower concentrations of
nutrients.B.Oligotrophic lakes are more subject to oxygen
depletion.C.Sediments in oligotrophic lakes contain larger
amounts of decomposable organic matter.D.Eutrophic lakes are
richer in nutrients.E.Rates of photosynthesis are lower in
eutrophic lakes.

A.removing carbon dioxide from the atmosphere.B.regulating the
pH of freshwater biomes and terrestrial groundwater.C.producing
a substantial amount of the biosphere's oxygen.D.being the
source of most of Earth's rainfall.E.moderating the climate of
terrestrial biomes.

B

46

When climbing a mountain, we can observe transitions in biological
communities that are analogous to the changes

A.in an ecosystem as it evolves over time.B.across the United
States from east to west.C.in a community through different
seasons.D.in biomes at different latitudes.E.at different
depths in the ocean.

D

47

Suppose that the number of bird species is determined mainly by the
number of vertical strata found in the environment. If so, in which of
the following biomes would you find the greatest number of bird species?

In ecological terms, disturbance is an event such as a storm, fire,
or human activity that changes a community, removing organisms and
altering resource availability. Which of the following statements
about the effects of disturbance is correct?

A.The effects of disturbance on a community are almost always
negative.B.Disturbances can create patches of different habitats
in a community.C.A healthy community is in an equilibrium state
of balance, with few disturbances.